Bug: fix panic on nil user fetch

[matoszz]

I randomly had an existing local UI session and needed to purge the core server / restart, so i did that, and when I went to the browser the URL was on localhost:3001/policies (or similar, and probably had existing cookies and tokens) and when i refreshed the page, i got a huge flood of panics from the core server console

  1({0x125914078, 0x1f05937b2cc0})
      /Users/manderson/go/pkg/mod/github.com/theopenlane/echo-prometheus@v0.1.0/middleware.go:109 +0xec
  github.com/theopenlane/echox/middleware.BodyDumpConfig.ToMiddleware.func1.1({0x125914078, 0x1f05937b2cc0})
      /Users/manderson/go/pkg/mod/github.com/theopenlane/echox@v0.3.0/middleware/body_dump.go:76 +0x27c
  github.com/theopenlane/echox/middleware.RecoverConfig.ToMiddleware.func1.1({0x125914078, 0x1f05937b2cc0})
      /Users/manderson/go/pkg/mod/github.com/theopenlane/echox@v0.3.0/middleware/recover.go:115 +0xd8
  github.com/theopenlane/core/pkg/logx.LoggingMiddleware.func1.1({0x125914230, 0x1f05955f4000})
      /Users/manderson/core/pkg/logx/middleware.go:125 +0x438
  github.com/theopenlane/echox/middleware.RequestIDConfig.ToMiddleware.func1.1({0x125914230, 0x1f05955f4000})
      /Users/manderson/go/pkg/mod/github.com/theopenlane/echox@v0.3.0/middleware/request_id.go:65 +0xec
  github.com/theopenlane/echox.(*Echo).ServeHTTP(0x1f0594db25a0, {0x1257dba60, 0x1f0593481770}, 0x1f059cbd97c0)
      /Users/manderson/go/pkg/mod/github.com/theopenlane/echox@v0.3.0/echo.go:692 +0x194
  net/http.serverHandler.ServeHTTP({0x12577abb0?}, {0x1257dba60?, 0x1f0593481770?}, 0x1?)
      /Users/manderson/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.26.3.darwin-arm64/src/net/http/server.go:3311 +0xb0
  net/http.(*conn).serve(0x1f0594d582d0, {0x1257f3718, 0x1f05925a5a10})
      /Users/manderson/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.26.3.darwin-arm64/src/net/http/server.go:2073 +0x7f4
  created by net/http.(*Server).Serve in goroutine 1
      /Users/manderson/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.26.3.darwin-arm64/src/net/http/server.go:3464 +0x2e0

  goroutine 1 [IO wait]:
  internal/poll.runtime_pollWait(0x134515800, 0x72)
      /Users/manderson/go/pkg/mod/golang.org/toolchain@v0.0.1-go1.26.3.darwin-arm64/src/runtime/netpoll.go:351 +0x48
  internal/poll.(*pollDesc).wait(0xffffffffffffffff?, 0x1045709bc?, 0x0)
      /Users/manderson/go/pkg/mod/golang.org/too user_agent=Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36
  12:52PM ERR internal/httpserve/server/stacktrace.go:39 | Error handling POST to /v1/refresh error=code=500, message=internal server error query=map[] remote_ip=::1 request_id=GyntwomaIQcuVbyDTllLJnPCUXaESTlB request_protocol=HTTP/1.1 severity=ERROR url=/v1/refresh user_agent=Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/148.0.0.0 Safari/537.36

On a not-found error, getUserDetailsByID returns nil, err, and dereferences user.ID on the nil user; that's the nil pointer panic. This change prevents the panic in that branch.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
50.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud